package jay;

public class yuxi {

	public static void main(String[] args) {
				int i=0,sum;
		System.out.println("请输入一个正整数:");
		Scanner input=new Scanner(System.in);
		sum=input.nextInt();
		i=sum;
		while(i>10){
			i=i/10;
		}
		System.out.println(i);
		

	}

}
